Axel Unbehaun

Transapical Aortic Valve Implantation: Incidence and Predictors of Paravalvular Leakage and Transvalvular Regurgitation in a Series of 358 Patients

OBJECTIVES The aim of this study was to evaluate the results when the surgical concept of not accepting intraprocedural paravalvular leakage was applied for transcatheter aortic valve implantation (TAVI). BACKGROUND The surgical strategy of conventional aortic valve replacement does not accept paraprosthetic leakage and requires immediate action to eliminate it. However, paravalvular leakage is the major concern after TAVI. METHODS A total of 358 patients underwent transapical TAVI with balloon-expandable prostheses. The modified procedural strategy consisted of precise positioning of the prosthesis using a modified TAVI technique and immediate additional intraprocedural treatment to eliminate relevant paravalvular leakage. RESULTS Balloon redilation of the transcatheter valve was performed in 18 patients (5%), and additional second valves were implanted in 13 (4%). At the end of the procedure, 186 patients (52%) had no paravalvular or transvalvular regurgitation. In the remaining 172 patients, paravalvular leakage was observed in 113 (32%), transvalvular leakage in 47 (13%), and both in 12 (3%). Leakage was trace in 88 patients (25%), mild in 82 (23%), and moderate in 2 (0.6%). Multivariate analysis identified male sex, New York Heart Association functional class IV, and no previous aortic valve replacement as predictors of post-procedural leakage. Cumulative survival was not dependent on post-procedural regurgitation rate. Overall mortality was 5 ± 1% at 30 days, 14 ± 2% at 6 months, 17 ± 2% at 1 year, and 33 ± 4% at 2 years. CONCLUSIONS The modified procedural strategy of transapical TAVI with a balloon-expandable prosthesis was associated with a low incidence of relevant prosthetic regurgitation.

Transapical aortic valve implantation in 175 consecutive patients: excellent outcome in very high-risk patients.

OBJECTIVES The aim of this study was to evaluate the outcome of transapical aortic valve implantation in a single center with expanded procedural experience and to compare it with predicted risk for conventional aortic valve surgery. BACKGROUND Transapical aortic valve implantation is a new approach for high-risk patients with severe aortic stenosis. There are only limited single-center experiences with very small numbers of patients. METHODS Since April 2008, transapical aortic valve implantation was performed in 175 consecutive patients. The mean patient age was 79.8 +/- 9 years, with a range of 36 to 97 years. The mean Society of Thoracic Surgeons score was 23.5 +/- 19.4% (range 2.7% to 89.5%); 98.3% of patients were in New York Heart Association functional class III or IV. Ten patients were in cardiogenic shock. RESULTS Technical success of the procedure was 100%. There was no conversion to conventional surgery. Cardiopulmonary bypass was used in 8 patients (6 elective, 2 emergency). The 30-day mortality was 5.1% for the entire group, 3.6% for all patients without cardiogenic shock, and 30% for the patients with cardiogenic shock. Survival at 1, 6, and 12 months was 94.9%, 85.5%, and 82.6%, respectively. CONCLUSIONS The outcome of transapical aortic valve implantation was very favorable and already reproducible during the learning curve. The method has become de facto our institutional primary choice for treatment of high-risk patients with severe aortic valve stenosis.

Transcranial Doppler sound detection of cerebral microembolism during transapical aortic valve implantation.

OBJECTIVE Transapical aortic valve implantation (TAVI) is a new method that might reduce the surgical risk of conventional surgical aortic valve replacement in very high-risk patients. Increased downstream microembolization is expected in transapical aortic valve implantation. However, whether it usually occurs, how often, and its clinical relevance are not known. We report the results of ultrasound microembolic signal detection in the middle cerebral artery during the procedure. METHODS Fifty patients (mean age: 80 ± 5 years; mean EuroSCORE: 36 ± 13 %) underwent transapical aortic valve implantation. Intraoperative transcranial Doppler (TCD) sound examination of both middle cerebral arteries (MCA) was used to identify high-intensity transient signals (HITS) and microembolic signals (MES) during seven phases of the procedure. Pre- and postoperative computed tomography of the brain and clinical neurological examinations were performed preoperatively and daily during the first postoperative week. RESULTS During the procedure, HITS [right MCA: 435 ± 922 (range 9-5765); left MCA: 471 ± 996 (range 24-6432)] and MES [right MCA: 78 ± 172 (range 1-955); left MCA: 62 ± 190 (range 2-1553)] were detected in all patients. Most of the MES were recorded during valvuloplasty [right MCA: 3 ± 5.6 (range 0-31); left MCA: 2 ± 4.9 (range 0-30)] and positioning of the prosthetic valve in the aortic position [right MCA: 6 ± 5 (range 0-22); left MCA: 2 ± 6.9 (range 0-38)]. Postoperatively, there were no clinical signs of new cerebral embolism. CONCLUSIONS Cerebral microemboli were detected by intraoperative transcranial Doppler sound examinations in all patients during transapical aortic valve implantation. Most of the signals were detected during balloon valvuloplasty and delivery of the prosthetic valve.

TAVI for Pure Aortic Valve Insufficiency in a Patient With a Left Ventricular Assist Device

We report transcatheter aortic valve implantation (TAVI) for pure aortic valve insufficiency in a patient with an otherwise normal aortic valve and a long-term left ventricular assist device (LVAD). An oversized 29-mm Edwards SAPIEN valve (Edwards Lifesciences, Irvine, CA) was implanted in the 21-mm native aortic valve annulus. Despite the complete absence of aortic calcifications, the prosthesis remained stably anchored inside the annulus. The reported experience demonstrates that TAVI is feasible even in patients with pure aortic valve regurgitation and can be a reasonable option in patients with aortic regurgitation after LVAD implantation.

Standardized immune monitoring for the prediction of infections after cardiopulmonary bypass surgery in risk patients

Infections are the most common cause of late complications in cardiopulmonary bypass (CPB) surgery patients, and are difficult to predict. Here we studied the diagnostic value of a standardized immune monitoring program based on recent advances in flow cytometry (exact quantification of surface‐marker expression) and cytokine determination (semiautomatic systems).

Rupture of the Device Landing Zone During Transcatheter Aortic Valve Implantation A Life-Threatening But Treatable Complication

Background— Iatrogenic damage of different structures of the aortic root, in the region of the so-called “device landing zone,” may occur during transcatheter aortic valve implantation (TAVI). It is mostly considered difficult to treat or even untreatable. Methods and Results— We performed a retrospective analysis of the occurrence, clinical presentation, treatment, and outcome of iatrogenic rupture in the device landing zone in a series of 618 consecutive patients who underwent TAVI at our institution between April 2008 and October 2011. The incidence of rupture was 1% (6 patients). The correct diagnosis was established during TAVI procedures in 4 and postmortem in 2 patients. The major sign of the aortic rupture was apparent bleeding in 4 patients and failure of myocardial recovery after valve implantation in 1; it was asymptomatic in 1 patient. The iatrogenic rupture in the region of the device landing zone was treated surgically in 5 patients and only conservatively in the patient without symptoms. When the diagnosis was established correctly during TAVI, only 1 of 4 patients died (25%). The overall mortality rate was 50% (3 of 6 patients died). Conclusions— Rupture of different structures in the device landing zone during TAVI is a life-threatening complication that can be treated successfully if it is immediately recognized and adequately managed.

Improved Technique of Transapical Aortic Valve Implantation: “The Berlin Addition”

Transapical aortic valve implantation carries some degree of uncertainty regarding the definitive valve position. We added angiographic visualization of the aortic root while the prosthetic valve is being slowly deployed. It enables easy correction of the position of the valve so that perfect alignment can be achieved of the relationships between the prosthetic valve, aortic valve annulus, aortic cusps, and the coronary arteries.

Annular Rupture During Transcatheter Aortic Valve Replacement: Classification, Pathophysiology, Diagnostics, Treatment Approaches, and Prevention

Annular rupture is an umbrella term covering different procedural-related injuries that may occur in the region of the aortic root and the left ventricular outflow tract during transcatheter aortic valve replacement. According to the anatomical location of the injury, there are 4 main types: supra-annular, intra-annular, subannular, and combined rupture. Annular rupture is a rare, unpredictable, and potentially fatal complication. It can be treated successfully if it is immediately recognized and adequately managed. The type of therapy depends on the location of the annular rupture and the nature of the clinical manifestations. Treatment approaches include conventional cardiac procedure, isolated pericardial drainage, and conservative therapy. This summary describes theoretical and practical considerations of the etiology, pathophysiology, classification, natural history, diagnostic and treatment strategies, and prevention approaches of annular rupture.

Negative pressure wound therapy for post-sternotomy mediastinitis reduces mortality rate and sternal re-infection rate compared to conventional treatment

OBJECTIVE Negative pressure wound therapy (NPWT) is a recently introduced treatment modality for post-sternotomy mediastinitis. The aim of this study was to compare the mortality rate, the sternal re-infection rate and the length of hospital stay in patients with post-sternotomy mediastinitis after NPWT and conventional treatment. METHODS We retrospectively analysed 118 patients with post-sternotomy mediastinitis after cardiac surgery. One group of 69 patients was treated with NPWT and the other group of 49 patients with conventional therapy. RESULTS There were no major differences between the two groups concerning preoperative data (EuroScore) or primary cardiac surgery (mainly coronary artery bypass grafting). NPWT therapy was found to reduce mortality rate (P=0.005) and sternal re-infection rate (P=0.008) compared with conventional treatment and tended to lead to a shorter length of hospital stay (P=0.08). CONCLUSIONS NPWT for post-sternotomy mediastinitis demonstrates encouraging clinical results with a reduction of the mortality rate and the sternal re-infection rate compared with conventional treatment. The results support NPWT as the first-line treatment for deep sternal wound infections.

State-of-the-Art ReviewAnnular Rupture During Transcatheter Aortic Valve Replacement: Classification, Pathophysiology, Diagnostics, Treatment Approaches, and Prevention

Annular rupture is an umbrella term covering different procedural-related injuries that may occur in the region of the aortic root and the left ventricular outflow tract during transcatheter aortic valve replacement. According to the anatomical location of the injury, there are 4 main types: supra-annular, intra-annular, subannular, and combined rupture. Annular rupture is a rare, unpredictable, and potentially fatal complication. It can be treated successfully if it is immediately recognized and adequately managed. The type of therapy depends on the location of the annular rupture and the nature of the clinical manifestations. Treatment approaches include conventional cardiac procedure, isolated pericardial drainage, and conservative therapy. This summary describes theoretical and practical considerations of the etiology, pathophysiology, classification, natural history, diagnostic and treatment strategies, and prevention approaches of annular rupture.